Not a perfect match

Burleigh Bailey
Chris Fleece
Parker Hannifin Corp.
Tube Fittings Div.
Columbus, Ohio

Questions often arise in regards to compatibility and interchangeability between different kinds of 60° cone fittings. Sixty-degree cone (BSPP) fittings typically serve as hose adapters on "low-cost" hydraulic systems from Asia and Europe. This is similar to how NPSM pipe swivels are typically used in the U.S. on equipment such as log splitters and other low-end hydraulic farm machinery.

The two main styles of cone fittings conform to either British Standard BS 5200 or Japanese Industrial Standard JIS B8363. Both are designed as adapters rather than tube connections. And both seal by metal-to-metal line contact between the conical surface of the internal seat and a corresponding surface on the mating component. Although cone angles and threads are identical, there are instances when these fittings will not function properly if interchanged.

Here is a review of the similarities, differences, and interchangeability of these two 60° cone fittings.

• The seat angle is 60° for both styles.
• Both use British Standard Pipe, Parallel (BSPP) thread.
• Both have an undercut at the back of the threads near the hex.

• Each conforms to a different standard, British Standard BS 5200 or Japanese Industrial Standard JIS B8363.
• Thread lengths are shorter on BS 5200 adapters. (See dimension "A" in the accompanying table.)
• The 60° cone diameter differs for each type. (See dimension "B" in the table.)
• The BS 5200 can also be used as a port fitting. A tapered undercut on some versions of the adapter helps locate a loose seal when used as a port fitting. The taper centers the port's bonded seal for proper sealing.
• BS 5200 adapters include Size 10 (5/8 in.) and JIS adapters do not.

Identification: There is no standard for identifying these fittings. Parker Hannifin, for example, marks JIS adapters with "JIS" on the hex or forging flats for visual identification. BS 5200 adapters do not carry a mark. Also, BS 5200 adapters may or may not have the tapered undercut.

Compatibility with hose fittings: Both adapters connect to hose fittings if the connection meets the appropriate standard.

Interchangeability: BS 5200 adapters do not mate with JIS swivel connections. JIS adapters might mate with BS swivels but these fittings should not be considered interchangeable because they were not designed as such.

The International Standards Organization is developing a standard to replace BS 5200 and JIS, based mostly on the BS 5200 standard. In the meantime, while BS 5200 and JIS 8363 adapters are similar, in some instances they are not interchangeable. So the best advice is to avoid mixing them inappropriately.